There are many kinds of plastic bags and their specifications are uncertain. Therefore, the design and production staff often overlook the bag-making method. As a result, although the design drafts are exquisite, the resulting finished product packages are unsatisfactory and even become waste products. Experience tells us that only by understanding the types of commonly-used packaging products can we make full use of design ideas, eliminate design items that do not meet the bag making process, and design a practical and perfect finished product package.
Plastic bags can be divided into three sides seals, middle bottom seals, three-dimensional seals and sheet materials according to bagging methods.
The three-side seals are sealed around the packaging bag. The front and back dimensions are all finished dimensions, have a certain sense of integrity, and the design is not restricted, and the front and rear designs have a certain degree of consistency. Because the front and back dimensions are the same, the front can be designed to allow the back and front to echo. At the time of plate making, they are arranged on the same platen roller.
The bottom seal is sealed on the back, the front size is the finished product size, the back is divided into two equal parts, and the sum of its width is equal to the width of the front surface. Usually, the front and back sides are unfolded during design, and the integrated design is implemented. Each plus 1cm edge, front and back are also on the same platen roller.
The three-dimensional seal is based on the mid-bottom seal, plus three-dimensional sides on both sides, the front and back sides are also on the same platen roller.
Due to the limitation of the printing material, the sheet material must be designed separately on the front and back sides, separately from the plate making, and cannot be on the same plate cylinder at the same time.